Insecticidal efficacy of neem (Azadirachta indica A. Juss.) products against the sweet potato (Ipomea batatas L.) weevil (Cylas puncticollis Boh.) in storage

Abstract

The insecticidal efficacy of neem in storage at Dang (Ngaoundere) and Kismatari (Garoua) was investigated in the present study under controlled conditions for two consecutive years (2013, 2014). In each of the studied site and and during each year, a factorial fully randomized block design ((3x2) x 4) was adopted, with two varieties (local and TIB1) as the first factor, and treatments (Neem oil, Neam leaves Extract, Control) as the second factor, each of which was repeated four times. The rate and severity of attacks, as well as the population dynamic of Cylas puncticollis were assessed. Results indicate that, after 2 months of storage, neem oil has proven to be the best bi-oinsecticide to preserve the two varieties of sweet potato grown in storage, causing 100% mortality of the weevils, and 0% attack of tubers. The neem leaves extract also significantly (p